U.S. patent number 4,325,836 [Application Number 06/170,262] was granted by the patent office on 1982-04-20 for novel titanium halide containing catalyst.
This patent grant is currently assigned to Stauffer Chemical Company. Invention is credited to Ronald A. Epstein, Robert I. Mink.
United States Patent |
4,325,836 |
Epstein , et al. |
April 20, 1982 |
**Please see images for:
( Certificate of Correction ) ** |
Novel titanium halide containing catalyst
Abstract
A novel catalyst system for the polymerization of alpha-olefins
is provided. The catalyst system comprises: (a) an organoaluminum
containing component, e.g. triethyl aluminum, and (b) a titanium
halide containing component. The titanium halide containing
component is obtained by reacting a halogen containing magnesium
compound, e.g. MgCl.sub.2, with an organic phosphite, e.g.
triphenyl phosphite, to produce a reaction product. The reaction
product is then co-pulverized with a complex of a titanium halide
compound and an electron donor compound, e.g. TiCl.sub.4.ethyl
benzoate, to produce a co-pulverized product. The co-pulverized
product is then reacted with a titanium halide compound, e.g.
TiCl.sub.4. A novel titanium halide containing component is
provided as well as a process for producing said component. A
process for the polymerization of alpha-olefins is also
provided.
Inventors: |
Epstein; Ronald A. (Yonkers,
NY), Mink; Robert I. (Yonkers, NY) |
Assignee: |
Stauffer Chemical Company
(Westport, CT)
|
Family
ID: |
22619197 |
Appl.
No.: |
06/170,262 |
Filed: |
July 18, 1980 |
Current U.S.
Class: |
502/105; 502/121;
526/124.9; 526/125.6 |
Current CPC
Class: |
C08F
4/022 (20130101); C08F 10/00 (20130101); C08F
10/00 (20130101); C08F 4/6545 (20130101) |
Current International
Class: |
C08F
4/00 (20060101); C08F 10/00 (20060101); C08F
4/02 (20060101); C08F 004/64 () |
Field of
Search: |
;252/429B |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Chem. Ab. 92:129640n, Japanese Tokkyo Kono 79 34,429, Kuroda et
al..
|
Primary Examiner: Garvin; Patrick
Attorney, Agent or Firm: Friedlander; Henry Z.
Claims
We claim:
1. A catalyst system comprising:
(a) an organoaluminum containing component; and
(b) a titanium halide containing component obtained by:
(i) reacting a halogen containing magnesium compound with an
organic phosphite to produce a reaction product;
(ii) co-pulverizing the reaction product with a complex of a
titanium halide compound and an electron donor compound to produce
a co-pulverized product; and
(iii) reacting the co-pulverized product with a titanium halide
compound.
2. The system of claim 1 wherein the halogen containing magnesium
compound is MgCl.sub.2.
3. The system of claim 1 wherein the organic phosphite used is from
about 0.01 to about 10 moles of phosphite per mole of magnesium
compound.
4. The system of claim 1 wherein the organic phosphite has the
formula: ##STR4## wherein R.sub.1, R.sub.2 and R.sub.3 are each
independently selected from the group consisting of alkyl from 1 to
20 carbon atoms, aryl and alkyl substituted aryl wherein the aryl
substituent is from 6 to 18 carbon atoms and the alkyl substituent
is from 1 to 20 carbon atoms.
5. The system of claim 4 wherein R.sub.1, R.sub.2 and R.sub.3 are
the same.
6. The system of claim 1 wherein the organic phosphite is a triaryl
phosphite.
7. The system of claim 1 wherein the organic phosphite is triphenyl
phosphite.
8. The system of claim 1 wherein the complex is a TiCl.sub.4.ethyl
benzoate complex.
9. The system of claim 1 wherein the titanium halide compound used
in reacting step (iii) is a titanium trichloride material.
10. The system of claim 1 wherein the titanium halide compound used
in reacting step (iii) is titanium tetrachloride.
11. The system of claim 1 wherein the quantity of titanium present
in the titanium halide containing component is about 0.1% to about
10% by weight, expressed as titanium metal.
12. The system of claim 1 wherein the organoaluminum containing
component comprises an organoaluminum compound and an electron
donor selected from the group consisting of esters of carboxylic
acids.
13. The system of claim 1 wherein the organoaluminum component
comprises an organoaluminum compound and an ester of an aromatic
carboxylic acid.
14. The system of claim 1 wherein the organoaluminum containing
component comprises triethyl aluminum and ethyl anisate or ethyl
benzoate.
15. A titanium halide containing component obtained by:
(i) reacting a halogen containing magnesium compound with an
organic phosphite to produce a reaction product;
(ii) co-pulverizing the reaction product with a complex of a
titanium halide compound and an electron donor compound to produce
a co-pulverized product; and
(iii) reacting the co-pulverized product with a titanium halide
compound.
16. The component of claim 15 wherein the halogen containing
magnesium compound is MgCl.sub.2.
17. The compound of claim 15 wherein the organic phosphite used is
from about 0.01 to about 10 moles of phosphite per mole of
magnesium compound.
18. The component of claim 15 wherein the organic phosphite has the
formula: ##STR5## wherein R.sub.1, R.sub.2 and R.sub.3 are each
independently selected from the group consisting of alkyl from 1 to
20 carbon atoms, aryl and alkyl substituted aryl wherein the aryl
substituent is from 6 to 18 carbon atoms and the alkyl substituent
is from 1 to 20 carbon atoms.
19. The component of claim 18 wherein R.sub.1, R.sub.2 and R.sub.3
are the same.
20. The component of claim 15 wherein the organic phosphite is a
triaryl phosphite.
21. The component of claim 15 wherein the organic phosphite is
triphenyl phosphite.
22. The component of claim 15 wherein the complex is a
TiCl.sub.4.ethyl benzoate complex.
23. The component of claim 15 wherein the titanium halide compound
used in reacting step (iii) is a titanium trichloride material.
24. The component of claim 15 wherein the titanium halide compound
used in reacting step (iii) is titanium tetrachloride.
25. The component of claim 15 wherein the quantity of titanium
present in the titanium halide containing component is about 0.1%
to about 10% by weight, expressed as titanium metal.
26. A process for producing a titanium halide containing component
comprising:
(i) reacting a halogen containing magnesium compound with an
organic phosphite to produce a reaction product;
(ii) co-pulverizing the reaction product with a complex of a
titanium halide compound and an electron donor compound to produce
a co-pulverized product; and
(iii) reacting the co-pulverized product with a titanium halide
compound.
27. The process of claim 26 wherein the halogen containing
magnesium compound is MgCl.sub.2.
28. The process of claim 26 wherein the organic phosphite used is
from about 0.01 to about 10 moles of phosphite per mole of
magnesium compound.
29. The process of claim 26 wherein the organic phosphite has the
formula: ##STR6## wherein R.sub.1, R.sub.2 and R.sub.3 are each
independently selected from the group consisting of alkyl from 1 to
20 carbon atoms, aryl and alkyl substituted aryl wherein the aryl
substituent is from 6 to b 18 carbon atoms and the alkyl
substituent is from 1 to 20 carbon atoms.
30. The process of claim 29 wherein R.sub.1, R.sub.2 and R.sub.3
are the same.
31. The process of claim 26 wherein the organic phosphite is a
triaryl phosphite.
32. The process of claim 26 wherein the organic phosphite is
triphenyl phosphite.
33. The process of claim 26 wherein the complex is a
TiCl.sub.4.ethyl benzoate complex.
34. The process of claim 26 wherein the titanium halide compound
used in reacting step (iii) is a titanium trichloride material.
35. The process of claim 26 wherein the titanium halide compound
used in reacting step (iii) is titanium tetrachloride.
36. The process of claim 26 wherein the quantity of titanium
present in the titanium halide containing component is about 0.1%
to about 10% by weight, expressed as titanium metal.
37. The system of claim 1 wherein the halogen-containing magnesium
compound is a solid selected from the group consisting of magnesium
chloride, magnesium bromide, magnesium iodide, ethoxy magnesium
chloride, butoxy magnesium chloride, and magnesium phenoxy
halide.
38. The component of claim 15 wherein the halogen-containing
magnesium compound is a solid selected from the group consisting of
magnesium chloride, magnesium bromide, magnesium iodide, ethoxy
magnesium chloride, butoxy magnesium chloride, and magnesium
phenoxy halide.
39. The process of claim 26 wherein the halogen-containing
magnesium compound is a solid selected from the group consisting of
magnesium chloride, magnesium bromide, magnesium iodide, ethoxy
magnesium chloride, butoxy magnesium chloride, and magnesium
phenoxy halide.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a novel catalyst system for the
polymerization of alpha-olefins, a novel titanium halide containing
catalyst component used in said system, a process for producing
said component and a process for the polymerization of
alpha-olefins using such catalyst system.
2. Prior Art
The polymerization of alpha-olefins in the presence of a catalyst
system comprising: (a) an organoaluminum containing component, and
(b) a titanium halide containing component is well known in the art
and the polymers produced utilizing such catalyst systems have
found numerous uses. The resulting crystalline polymers have
associated therewith, to a greater or lesser degree, a low
molecular weight amorphous polymer. The production of polymers
having a low concentration of such amorphous polymers results in a
polymer having highly desirable properties. The production of
highly stereoregular crystalline polymers is thus a desirable
objective for a catalyst system and polymerization process.
It is also desirable that high amounts of polymer be produced per
unit of time per unit of catalyst employed, i.e. the catalyst
system have a high activity. Ideally, it is highly desirable to
simultaneously improve the stereospecificity and activity of a
catalyst system.
Various approaches to achieving the aforementioned objectives have
been proposed in the art.
South African Pat. No. 78/1023 to Toyota et al. describes producing
a titanium halide containing component by reacting a mechanically
pulverized product of an organic acid ester and a halogen
containing magnesium compound, with an active hydrogen containing
organic compound in the absence of mechanical pulverization. The
resulting reaction product is then reacted with an organometallic
compound of a metal of Groups I to III of the Periodic Table in the
absence of mechanical pulverization. The resulting solid reaction
product is then washed with an inert organic solvent, and the
resultant solid reacted with a titanium compound in the absence of
mechanical pulverization. The resultant solids are then separated
from the reaction system. This reference, however, does not teach
reacting with an organic phosphite and requires an active hydrogen
containing organic compound and an organometallic compound.
U.S. Pat. No. 4,143,223 to Toyota et al. describes reacting a
mechanically co-pulverized solid component of, for example,
magnesium chloride, an organic acid ester and an active hydrogen
containing compound, e.g. phenol, with a tetravalent titanium
compound, e.g. TiCl.sub.4. This reference does not teach reacting
with an organic phosphite.
Japanese Tokkyo Koho No. 79 34,429 to Kuroda et al. (as reported in
CA 92:129640n) polymerizes ethylene using a mixture of
trialkylaluminum, alkylhaloaluminum, and a ball milled solid
product of Mg halide, phosphite esters, Ti(IV) compounds and
Ti(III) compounds. This titanium halide containing component is
produced by a different process using different ingredients than
the invention described herein.
U.S. Pat. No. 4,130,503 to Fodor describes a catalyst component
comprising a magnesium chloride support, a titanium trichloride, an
aluminum trichloride and an organic phosphite. Exemplary of such a
component is an MgCl.sub.2 supported TiCl.sub.3.1/3AlCl.sub.3 plus
triphenyl phosphite catalyst component. This reference, however,
does not describe the use of an electron donor compound or
TiCl.sub.4 and generally relates to a different class of catalyst
components with respect to the activity thereof.
U.S. Pat. No. 3,953,414 to Galli et al. describes the use of
triphenyl phosphine and triisobutyl aluminum in conjunction with a
titanium halide containing catalyst component prepared in a
specific manner from MgCl.sub.2 and TiCl.sub.4. This reference does
not describe producing the titanium halide containing catalyst
component of this invention.
Additionally, in the Assignee's U.S. Ser. No. 163,615, filed June
23, 1980, the titanium halide containing component is obtained by
co-pulverizing a halogen containing magnesium compound with an
electron donor compound. This is then reacted with an organic
phosphite to produce a reaction product which is then reacted with
a titanium halide compound. This does not teach or suggest reacting
the magnesium compound with an organic phosphite followed by a
complex of a titanium halide material and an electron donor.
Other references of interest are U.S. Pat. Nos. 4,148,756 to
Langer; 4,013,823 to Longi et al., 4,146,502 to Yokayama et al.;
4,107,414 to Giannini et al. and 3,642,746 to Kashiwa et al.
SUMMARY OF THE INVENTION
In accordance with this invention, there is provided a novel
catalyst system for the polymerization of alpha-olefins. The
catalyst system comprises:
(a) an organoaluminum containing component; and
(b) a titanium halide containing component obtained by:
(i) reacting a halogen containing magnesium compound with an
organic phosphite to produce a reaction product;
(ii) co-pulverizing the reaction product with a complex of a
titanium halide compound and an electron donor compound to produce
a co-pulverized product;
(iii) reacting the co-pulverized product with a titanium halide
compound.
In accordance with another aspect of this invention, a process is
provided for the polymerization of alpha-olefins using the
aforesaid catalyst system.
In accordance with still another aspect of this invention, a novel
titanium halide containing component and a process for producing
said component are provided.
DETAILED DESCRIPTION OF THE INVENTION
The invention as described herein is broadly applicable to the
polymerization of olefins, corresponding to the formula
R--CH.dbd.CH.sub.2, wherein R is an alkyl radical containing from 1
to 8 inclusive carbon atoms, and hydrogen. The preferred olefins,
however, include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene
and the like. The term "polymer" as used herein includes both
homopolymers and copolymers, and the polymerization of mixtures of
alpha-olefins with minor proportions of ethylene, as well as the
polymerization of ethylene.
For the purposes of simplification the invention is described
herein with particular reference to the polymerization of
propylene, however, the invention is not to be so limited.
In the formation of the titanium halide containing component (b),
the first step (i) is to react a halogen containing magnesium
compound with an organic phosphite to produce a reaction product.
Preferably, this is done in the absence of mechanical
pulverization.
In the present application, the term "co-pulverizing",
"pulverization", etc. denote pulverization by suitable means by
bringing the reaction components into mutual contact, for example,
milling in a ball mill, vibratory mill or impact mill, and does not
include more mechanical stirring within its scope. Accordingly, the
term "absence of mechanical pulverization" means the absence of
such pulverizing means but does not preclude the presence of mere
mechanical stirring that is customarily used in chemical
reactions.
Preferably the reacting step (i) is carried out in the presence of
an inert organic liquid diluent such as hexane, heptane, kerosene
or toluene. The reaction can be performed, for example, by adding
the organic phosphite to a suspension of the magnesium compound in
an inert organic liquid diluent. The amount of the magnesium
compound is preferably about 10 to about 1,000 grams per liter of
diluent. The reaction is carried out preferably at a temperature of
about 0.degree. C. to about 150.degree. C. and a reaction time is,
for example, from about 10 minutes to about 10 hours. The amount of
the organic phosphite can be properly chosen and is preferably
about 0.01 to about 10 moles, more preferably about 0.1 to about 10
moles, per mole of the magnesium compound.
After the reaction, the unreacted organic phosphite is removed by
filtration or decantation, and the reaction product may be washed
with a suitable inert solvent such as hexane, heptane, or kerosene
to remove the soluble organic phosphite as much as possible. The
reaction product may then be dried.
The halogen containing magnesium compound is desirably a solid
which is preferably as anhydrous as possible, but the inclusion of
moisture in an amount which does not substantially affect the
performance of the catalyst is permissible. For the convenience of
handling, it is advantageous to use the magnesium compound as a
powder having an average particle diameter of about 0.1 to about 50
microns. Larger particles can be used, because they can be
pulverized during the co-pulverizing step (ii). The halogen
containing magnesium compound may be those which contain other
groups such as an alkoxy or phenoxy group, but magnesium dihalides
give the best results.
Examples of preferred halogen containing magnesium compounds are
magnesium dihalides such as magnesium chloride, magnesium bromide
and magnesium iodide. Magnesium chloride is the most preferred,
however, a magnesium phenoxy halide such as: ##STR1## may also be
used.
The organic phosphites used in this invention include
polyphosphites, for example, distearyl pentaerythritol diphosphite.
Preferably, however, the organic phosphites are of the formula:
##STR2## wherein R.sub.1, R.sub.2 and R.sub.3 are each
independently selected from the group consisting of alkyl from 1 to
20 carbon atoms, aryl and alkyl substituted aryl wherein the aryl
substituent is from 6 to 18 carbon atoms and the alkyl substituent
is from 1 to 20 carbon atoms, and cycloalkyl from 5 to 24 carbon
atoms.
Preferably, R.sub.1, R.sub.2 and R.sub.3 are the same.
Preferably, the organic phosphite in the titanium containing
catalyst component is an aryl phosphite or alkyl substituted aryl,
and more preferably a triaryl phosphite. Most preferred is
triphenyl phosphite (TPP). Other suitable phosphites are
tri-1-naphthyl phosphite, tri-9-anthryl phosphite,
tri-4-phenanthryl phosphite, tri-o-tolyl phosphite, tri-p-cumenyl
phosphite, tri-nonaphenyl phosphite, tri(cyclohexylphenyl)
phosphite, tri(6-cycloheptyl-2-naphthyl) phosphite,
tri(10-cyclodecyl-9-anthryl) phosphite, tri(3-cyclopentylphenyl)
phosphite, tri(4-12-naphthyl)phenyl phosphite,
tri(7-phenyl-1-naphthyl) phosphite, tri(6-phenyl-2-anthryl)
phosphite, tri(7-phenyl-1-phenanthryl) phosphite, and the like.
Other organic phosphites that may be used are the tri-methyl,
ethyl, propyl, etc. phosphites, tri-cyclohexyl phosphite, and the
aforementioned polyphosphites.
The reaction product is then co-pulverized with a complex of a
titanium halide compound and an electron donor compound to produce
a co-pulverized product, i.e. co-pulverizing step (ii).
In preparing the co-pulverized product, the reaction product from
step (i) and the complex may be separately fed in the free state
and mechanically pulverized or they may be contacted in advance to
form a complex or adduct, and mechanically pulverized in this
state. Alternatively, the product can be produced by co-pulverizing
compounds which can form the complex under mechanical
pulverization.
The mechanical pulverization is performed preferably in the
substantial absence of oxygen and water using, for example, a ball
mill, vibratory mill, or impact mill. The pulverization time,
although different from apparatus to apparatus, for example, is
about 1 hour to about 10 days. The pulverization can be performed
at room temperature, and it is not particularly necessary to heat
or cool the pulverization system. Where there is a vigorous
exotherm the pulverization system is preferably cooled by a
suitable means. The temperatures, for example, may be about
0.degree. to about 100.degree. C. Preferably, the pulverization is
carried out until the pulverized product attains a surface area of
at least 3 m.sup.2 /g, especially at least 30 m.sup.2 /g. The
pulverization is usually carried out in a single step, but if
desired may be carried out in a multiplicity of steps. For example,
it is possible first to pulverize the reaction product from step
(i) with, perhaps, pulverization aids (described hereinbelow) and
then add the complex and continue the pulverization.
The co-pulverizing step (ii) may be performed, but not necesarily,
in the presence of an organic or inorganic pulverization aid.
Examples of pulverization aids include inert liquid diluents such
as hexane, heptane and kerosene; organic solid diluents such as
polystyrene and polypropylene and inert inorganic solids such as
boron oxide, silicon oxides and organosiloxanes. The pulverization
aids can be used in an amount of about 0.01 to about 1 times the
weight of the reaction product from step (i).
The amount of complex used in forming the co-pulverized product of
step (ii) is about 0.01 to about 1 mole, preferably about 0.01 to
about 0.1 moles per mole of halogen containing magnesium
compound.
The titanium halide containing components in the complex contain a
halogen compound of either trivalent or tetravalent titanium.
Preferred titanium halides are a titanium trichloride material
(described below) and titanium tetrachloride.
The titanium trichloride material can be produced in a variety of
ways including:
(a) reaction of titanium tetrachloride with a metal such as
aluminum or titanium, the reduced titanium material being either
milled or unmilled;
(b) reduction of titanium tetrachloride with hydrogen;
(c) reduction of titanium tetrachloride with an organometallic
compound such as an aluminum alkyl; or
(d) grinding a combination of titanium trichloride and a halide of
a Group III metal, such as an aluminum halide.
Examples of suitable titanium trichloride materials are well known
in the art and are described in a number of publications and
patents, including U.S. Pat. Nos. 3,639,375 to Staiger et al. and
3,701,763 to Wada et al. which are each incorporated herein by
reference as showing the type of titanium trichloride material that
may be used in the present invention.
Examples of specific titanium halide compounds which may be
contained in the component are TiCl.sub.4, TiI.sub.4, Ti(OC.sub.3
H.sub.7)Cl.sub.3, Ti(OC.sub.4 H.sub.9).sub.2 CL.sub.2
3TiCl.sub.3.AlCl.sub.3, Ti[O-C(CH.sub.3)-CH-CO-CH.sub.3 ].sub.2
Cl.sub.2, Ti[N(C.sub.2 H.sub.5).sub.2 ]Cl.sub.3, Ti(OC.sub.6
H.sub.5)Cl.sub.3, Ti[N(C.sub.6 H.sub.5).sub.2 ]Cl.sub.3, Ti(C.sub.6
H.sub.5 COO)Cl.sub.3, [N(C.sub.4 H.sub.9).sub.4 ].sub.2 TiCl.sub.6
[N(CH.sub.3).sub.4 ]Ti.sub.2 Cl.sub.9, TiBr.sub.4, TiCl.sub.3
OSO.sub.2 C.sub.6 H.sub.5, and LiTi(OC.sub.3 H.sub.7).sub.2
Cl.sub.3.
The titanium halide compound, e.g. the titanium trichloride
material or titanium tetrachloride, is combined with an amount of
electron donor compound. Examples of suitable electron donor
compounds which can be used can be selected from those described in
U.S. Pat. Nos. 3,639,375 to Staiger et al. and 3,701,763 to Wada et
al. and those described below for use in the organoaluminum
containing component. The following classes of electron donor
compounds may be used:
Organic oxygen-containing compounds such as the aliphatic ethers,
aromatic ethers, aliphatic carboxylic acid esters, cyclic esters of
carbonic acid, aromatic carboxylic acid esters, unsaturated
carboxylic acid esters, aliphatic alcohols, phenols, aldehydes,
aliphatic carboxylic acids, aromatic carboxylic acids, aliphatic
carboxylic acid halides, lactones, aromatic carboxylic acid
halides, aliphatic ketones, aromatic ketones, and monoterpenic
ketones;
Organic nitrogen-containing compounds such as the aliphatic amines,
aromatic amines, heterocyclic amines, aliphatic nitriles, aliphatic
carbamates, aromatic nitriles, aromatic isocyanates and aromatic
azo compounds;
Mixed oxygen-nitrogen compounds such as the aliphatic and aromatic
amides and quanidine and its alkyl substituted derivatives;
Organic phosphorous-containing compounds such as the aliphatic
phosphines, aromatic phosphines;
Mixed phosphorus-nitrogen compounds such as the phosphoric
amides;
Sulfur-containing compounds such as carbon disulfide, the aliphatic
thioethers and the aromatic thioethers; and
Organic silicon-containing compounds including monomer type
compounds such as organoaminosilanes, organoalkoxysilanes,
organoaryloxysilanes, organosilicon isocyanates and organosilanol
carboxylic acid esters; and polymer type of compounds such as the
organopolysilanes, organopolysiloxanes,
.gamma.,.omega.-dihaloorganopolysiloxanes, organocyclopolysiloxanes
and polysilazanes.
Examples of some electron donor compounds are hexamethyl phosphoric
triamide, dimethyl formamide, benzonitrile, .gamma.-butyrolactone,
dimethyl acetamide, N-methyl pyrrolidone, N,N-dimethylpivalamide,
toluene diisocyanate, dimethyl thioformamide, ethylene carbonate,
tetramethyl guanidine and methyl carbamate. Other electron-donors
are: N,N,N',N'tetramethylenediamine, veratrol, ethyl benzoate,
acetone, 2,5-hexanedione, dimethylmaleate, dimethylmalonate,
tetrahydrofurfurylmethylether, nitrobenzene, diethyl carbonate,
acetophenone, 1,2,4-trimethyl piperazine, ethyl acetate.
Particularly preferred is ethyl benzoate. Others that can be used
in practicing the present invention are known to persons of skill
in the art.
Organic acid esters are particularly preferred electron donors.
The organic acid ester used in forming the complex is preferably
selected from the group consisting of aliphatic carboxylic acid
esters, halogenated aliphatic carboxylic acid esters, alicyclic
carboxylic acid esters, and aromatic carboxylic acid esters.
Preferred species are aliphatic carboxylic acid esters containing
up to 18 carbon atoms, halogenated aliphatic carboxylic acid esters
containing up to 18 carbon atoms, alicyclic carboxylic acid esters
containing up to 12 carbon atoms, and aromatic carboxylic acid
esters containing up to 26 carbon atoms.
Examples of such organic acid esters are esters formed between
carboxylic acids or halocarboxylic acids selected from the group
consisting of saturated or unsaturated aliphatic carboxylic acids
containing 1 to 8 carbon atoms, especially 1 to 4 carbon atoms and
their halogen-substitution products, and alcohols or phenols
selected from the group consisting of saturated or unsaturated
aliphatic alcohols containing 1 to 8 carbon atoms, especially 1 to
4 carbon atoms, saturated or unsaturated alicyclic alcohols
containing 3 to 8 carbon atoms, especially 5 to 6 carbon atoms,
phenols containing 6 to 10 carbon atoms, especially 6 to 8 carbon
atoms, and alicyclic or aromatic alcohols having a C.sub.1 -C.sub.4
aliphatic saturated or unsaturated alcohol moiety bonded to an
alicyclic or aromatic ring with 3 to 10 carbon atoms. Further
examples include esters formed between alicyclic carboxylic acids
containing 6 to 12 carbon atoms, especially 6 to 8 carbon atoms,
and saturated or unsaturated aliphatic alcohols containing 1 to 8,
especially 1 to 4, carbon atoms. There can also be cited esters
formed between aromatic carboxylic acids containing 7 to 12 carbon
atoms, especially 7 to 10 carbon atoms, and alcohols or phenols
selected from the group consisting of saturated or unsaturated
aliphatic alcohols containing 1 to 8 carbon atoms, especially 1 to
4 carbon atoms, and alicyclic or aromatic alcohols formed by a
C.sub.1 -C.sub.4 aliphatic saturated or unsaturated alcohol moiety
bonded to an alicyclic or aromatic ring with 3 to 10 carbon atoms,
and phenol.
Specific examples of the aliphatic carboxylic esters are primary
alkyl esters of saturated fatty acids such as methyl formate, ethyl
acetate, n-amyl acetate, 2-ethylhexyl acetate, n-butyl formate,
ethyl butyrate and ethyl valerate; alkenyl esters of saturated
fatty acids such as vinyl acetate and allyl acetate; primary alkyl
esters of unsaturated fatty acids such as methyl acrylate, methyl
methacrylate, and n-butyl crotonate, and halogen-substitution
products of these esters.
Specific examples of the alicyclic carboxylic acid esters include
methyl cyclohexanecarboxylate, ethyl cyclohexanecarboxylate, methyl
methylcyclohexanecarboxylate and ethyl
methylcyclohexanecarboxylate.
Specific examples of the aromatic carboxylic acid esters include
primary alkyl esters of benzoic acid such as methyl benzoate, ethyl
benzoate, n-propyl benzoate, n- or i-butyl benzoate, n- and i-amyl
benzoate, n-hexyl benzoate, n-octyl benzoate, and 2-ethylhexyl
benzoate; primary alkyl esters of toluic acid such as methyl
toluate, ethyl toluate, n- or i-butyl toluate, and 2-ethylhexyl
toluate; primary alkyl esters of anisic acid such as methyl
anisate, ethyl anisate, or n-propyl anisate; and primary alkyl
esters of naphthoic acid such as methyl naphthoate, n-propyl
naphthoate, n-butyl naphthoate, and 2-ethylhexyl naphthoate.
Of these compounds, the aromatic carboxylic acid esters are
preferred. Alkyl esters with 1 to 4 carbon atoms, particularly
methyl or ethyl esters, of benzoic acid, p-toluic acid or p-anisic
acid are especially preferred.
In the final step (iii) of forming the titanium halide containing
component in accordance with this invention, the resultant
co-pulverized product from step (ii) is reacted with a titanium
halide compound. The reaction is preferably carried out in the
absence of mechanical pulverization. This reaction can be performed
by suspending the reacted pulverized product in a liquid titanium
halide compound or a solution of a titanium halide compound in an
inert organic solvent, e.g. hexane, heptane, kerosene and
toluene.
The amount of the titanium halide compound used may be at least
about 0.1 mole, preferably at least about 1 mole per mole of
magnesium in the pulverized product from step (iii). The reaction
temperature is usually from room temperature to about 200.degree.
C. and the reaction time is about 10 minutes to about 5 hours. The
reaction may be performed for longer or shorter periods of time.
After the reaction, the unreacted titanium halide compound is
removed by filtration or decantation, and the reaction product may
be washed with a suitable inert solvent, such as hexane, heptane,
or kerosene to remove the soluble titanium compound as much as
possible.
The titanium halide compound used in reaction step (iii) may be the
same type as used in the aforementioned complex used in step (ii).
Titanium tetrachloride is particularly preferred.
The organoaluminum containing component of the catalyst system of
this invention contains the conventional organoaluminum compound
used in the polymerization of alpha-olefins using conventional
reaction conditions for such a polymerization. The organoaluminum
compounds which are particularly suitable are: alkylhaloaluminum
compounds having the formula AlR.sub.n X.sub.3-n, wherein R
represents C.sub.1-14 a saturated hydrocarbon residue; X represents
a halogen, particularly Cl and Br, and n is 2, 1.5 or 1; and alkyl
aluminum compounds having the formula AlR.sub.n (OR').sub.3-n where
R and n are defined above and R' represents a C.sub.1-14 saturated
hydrocarbon residue that can be the same as R. Trialkyl aluminums
having the formula AlRR'R", where R, R' and R" are the same or
different, and respectively represent a C.sub.1-14 saturated
hydrocarbon residue are particularly preferred.
The following are examples of suitable organoaluminum compounds:
trimethyl aluminum, triethyl aluminum, n-tripropyl aluminum,
n-tributyl aluminum, triisobutyl aluminum, trioctyl aluminum,
tridodecyl aluminum, methyl aluminum sesquichloride, ethyl aluminum
sesquichloride, diethyl aluminum chloride, ethyl aluminum
dichloride, dibutyl aluminum chloride, ethyl aluminum
sesquibromide, and mixtures thereof. Triethyl aluminum is a
particularly preferred organoaluminum compound for use in this
invention for the polymerization of propylene.
The organoaluminum compounds may also, for example, contain two or
more aluminum atoms linked together through an oxygen or a nitrogen
atom. These organoaluminum compounds are obtained by the reaction
of a trialkyl aluminum compound with water, ammonia or a primary
amine, according to known methods. Typical examples of such
compounds are: ##STR3##
The organoaluminum containing compound is preferably used in
combination with an electron donor (such as a Lewis base) to form
the organoaluminum containing component.
Suitable electron donor compounds are amines, amides, ethers,
esters, ketones, nitriles, phosphines, phosphoramides, aldehydes,
alcoholates, amides and the organic acid salts of metals belonging
to the first four groups of the Mendelyeev Periodic System. The
best residue, as regards both activity and stereospecificity, are
achieved when esters of carboxylic acids particularly esters of
aromatic acids, are used as the electron donors.
Examples of esters which can be used are: esters of aliphatic,
cycloaliphatic and aromatic mono- and polycarboxylic acids; esters
of alkoxy or amino acids; esters of inorganic acids like carbonic,
phosphorous, sulfuric, phosphoric and silicic acids. Examples of
specific compounds are: ethylbenzoate, methylbenzoate, methyl and
ethyl-p-methoxybenzoate, ethyl-n-butylbenzoate, ethyl-p- and
o-chlorobenzoate, ethyl-p-butoxybenzotate, isobutylbenzoate, methyl
and ethyl-p-methylbenzoate, ethylacetate, ethyl propionate,
ethyl-alpha-naphthoate, ethylcyclohexanoate, ethyl pivalate, ethyl
N,N-diethyl-carbamate, diethyl carbonate, diethylsulfate,
dimethylmaleate, ethylbenzenesulfonate, triethylborate,
ethylnaphthenate.
The organoaluminum compound/electron donor molar ratio can
generally be lower than 10:1 and, in the case of ester electron
donors, ranges from 10:1 to 2:1, and more particularly from 6:1 to
2:1.
For general guidance, the quantity of titanium present in the
titantium halide containing component is between about 0.1 and 10%
by weight, expressed as titanium metal. The Al/Ti molar ratio is
generally less than 1,000 and preferably less than 600, and most
preferably from about 100 to about 600.
The conditions under which the polymerization of alpha-olefins with
the aid of the catalyst system of this invention is conducted are
those known in the art. The polymerization is carried out at
temperatures ranging from -80.degree. C. to 150.degree. C.,
preferably from 40.degree. C. to 100.degree. C., operating with
partial pressures of the alpha-olefins higher than atmospheric
pressure. The polymerization can be carried out both in liquid
phase in the presence or in the absence of an inert diluent, or in
the gas phase. The alpha-olefins comprise in general olefins
CH.sub.2 .dbd.CHR in which R is an alkyl radical containing 1 to 8
inclusive carbon atoms and hydrogen. Propylene, 1-butene,
1-pentene, 4-methyl-1-pentene are preferred examples of
alphaolefins. As hereinbefore indicated the process can be used to
polymerize mixtures of alpha-olefins with minor proportions of
ethylene and also ethylene.
Examples of inert diluents which may be used in the polymerization
are the C.sub.4 -C.sub.8 aliphatic hydrocarbons, examples of which
are n-hexane, n-heptane, and cycloaliphatic hydrocarbons like
cyclohexane and the aromatic ones such as benzene, toluene, and
xylene.
The regulation of the molecular weight of the polymer during the
polymerization may also be carried out according to known methods,
e.g. operating in the presence of alkyl halides, Zn or Cd
organo-metallic compounds or hydrogen.
It has been found that the catalyst system of this invention has
enhanced stereospecificity and/or activity.
The following examples are given to better illustrate the present
invention and are not intended to be limiting.
POLYMERIZATION PROCEDURES
Slurry Polymerization
The following polymerization procedure was utilized.
A one gallon jacketed autoclave, i.e. the polymerization reactor,
equipped with a mechanical stirrer was charged with 2 liters of dry
heptane at about 45.degree. C. to 55.degree. C.
The catalyst system was then added to the autoclave as follows:
1. A nitrogen purge was passed through the autoclave and adjusted
to purge the port during the addition of the catalyst system. A
weighed quantity of the organoaluminum compound was added by
syringe and stirred for 5 or 10 seconds. A weighed quantity of the
required electron donor was then added through the port and the
reactor stirred for another 5 to 10 seconds. The solid titanium
halide containing catalyst component was then added. Propylene was
then injected into the autoclave to a pressure of 10 atmospheres
and the temperature maintained at 65.degree. C. During the
polymerization, additional propylene was fed as needed to maintain
this pressure. The polymerization test was carried out for 11/2
hours.
At the end of the polymerization, the polymer mixture was filtered,
washed with isopropanol, and oven dried at 70.degree. C. and
weighed to produce Dry Polymer. The polymerization solvent is
evaporated to determine heptane soluble polymer.
Bulk Polymerization
The following polymerization procedure was utilized.
A 2.8 l. jacketed autoclave, i.e. the polymerization reactor,
equipped with a mechanical stirrer was charged with the catalyst
system as follows:
1. A nitrogen purge was passed through the autoclave and adjusted
to purge the port during the addition of the catalyst system. A
weighed quantity of the organoaluminum compound was added by
syringe. A weighed quantity of the required electron donor was then
added through the port. The solid titanium halide containing
catalyst component was then added. 2 l. of liquid propylene was
then added to the autoclave and the temperature of the propylene
brought to 70.degree. C. The polymerization test was carried out
for 11/2 hours, except where noted.
At the end of the polymerization, the polymer mixture was filtered,
oven dried at 70.degree. C. and weighed to produce Dry Polymer.
Catalyst activity is defined herein as the ratio: ##EQU1##
In all examples, the activity is grams polypropylene per gram
catalyst.
The Dry Polymer is extracted with heptane for 3 hours in a Soxhlet
apparatus. The percentage heptane insolubles ("C.sub.7 ") is
defined as the percentage of the heptane insoluble fraction in the
Dry Polymer.
The Isotactic Index (II), a measure of the insoluble polymer
produced, is defined herein as: ##EQU2##
The total polymer produced includes the Dry Polymer and the polymer
produced which was soluble in the polymerization solvent.
EXAMPLE 1
16 grams of MgCl.sub.2 (0.17 moles) was reacted with 40 grams of
triphenyl phosphite (0.13 moles) in 100 milliliters of heptane at
95.degree.-100.degree. C. for 21/4 hrs. The product was filtered,
washed twice with 75 milliliters of heptane and vacuum dried. 15.4
grams of this product was then milled with 4.2 grams (12.4 mmol)
TiCl.sub.4.ethyl benzoate for 72 hours. 10 grams of the milled
product was slurried in 30 milliliters of heptane and reacted with
60 ml. (104 g., 0.55 moles) TiCl.sub.4 for 1 hour at 100.degree. C.
This final product was filtered, washed four times with 75
milliliters of heptane and vacuum dried. The activity of the
catalyst system for slurry polymerization using triethyl aluminum
and ethyl anisate at 4:1 molar ratio (12:3 mmol/mmol) as the
organoaluminum containing component was 6,082 grams of
polypropylene per gram catalyst, and the II was 87.3%; with
triethyl aluminum and methyl-p-toluate at the same molar ratio as
the organoaluminum containing component. The activity/II was
6020/90.5%.
* * * * *